But if it’s thrown out of whack, either into overproduction (hyperthyroidism) or underproduction (hypothyroidism), it can leave you wracked with anxiety.

“If you have anxiety, checking your thyroid should be a routine part [of treatment],” Myers tells The Post. “The thyroid in and of itself can cause mood disturbances, particularly if you have an overactive thyroid.”

She says stress and anxiety can also trigger a thyroid disorder by creating a high-cortisol state. “It’s a Catch-22,” Myers says.

Luckily, blood tests offer a tangible way to diagnose and treat the hard-to-manage illness.

“There’s not one blood test that says, ‘You have anxiety!’ ” Myers says. “[But] there are very concrete tests … to find out if you have thyroid dysfunction.”

She suggests asking your doctor for a full thyroid work-up, which includes testing for antibodies. There are other symptoms you can ask your doctor about, including elevated temperature and high blood pressure.

“You know your body better than anyone else,” Myers says. “If you intuitively feel like this is more than anxiety, or if it’s just come out of the blue, you need to get it checked out.”

To prevent thyroid irregularities, Myers suggests incorporating stress-relieving activities into your daily routine. Start with taking long, deep breaths. “It’s very hard to be anxious if you take five counts in and five counts out,” she says. From there, try adding a hot bath or meditation.

You could also try restorative workouts, like yoga. Just be wary of over-exercising, which Myers says can worsen a thyroid condition — and anxiety.

“I see CrossFit people coming into my clinic and their adrenal [glands] and thyroids are burnt out,” she says. “Some people are built to handle it, but many of us are not.”